Why join?

If confirmed, he will be tasked to help tackle terrorism and other security threats like cybercrime and radicalisation throughout the EU.

His portfolio was announced on Tuesday (2 August) by EU commission president Jean-Claude Juncker.

"I want the Commission which I preside to be a strong and political team. And I want you, with your political skills and experience, to fully play your part in this team," said Juncker in his mission letter to King.

King is replacing Jonathan Hill who resigned as financial stability commissioner in the wake of UK's referendum to leave the EU.

King was appointed to the Brussels-executive seat by David Cameron before he too resigned as prime minister.

The career diplomat, who is married to a senior EU commission official who has worked on counter-terrorism issues, is currently the UK's outgoing ambassador to France.

The EU commission, for its part, is playing down his nationality given the broader concerns over Britain's decision to leave the EU after an often 43-year tumultuous membership.

"He is not a commissioner from the UK. He will be a European Commissioner if confirmed," Mina Andreeva, a chief commission spokeswoman, told reporters in Brussels.

Andreeva said King's role will be, in part, to get EU states to better coordinate and share information in their counter-terrorism efforts.

King will have a "special advisor" contract once his role is formally accepted by the European Parliament in autumn.

Liberal group leader Guy Verhofstadt has already described King's security portfolio as odd.

"The country has a long-standing opt-out from justice and home affairs measures, the crucial policy area if one is serious about building a European anti-terrorism capacity," he said in a statement.

A Downing street spokesperson said in a statement that security is an issue best tackled with better cooperation across EU states.

"Security is a vital issue for all member states and co-operation across the EU can help to better protect us all from the range of threats we face," said the spokesperson.

King will report to EU commission vice-president Frans Timmermans and EU home affairs commissioner Dimitris Avramopoulos.

The European Commission, as guardian of the treaties, declines to sanction Italy's treatment of the Roma following a forced eviction on Thursday of some 300 from a camp in the outskirts of the Italian capital.